NBP rate for an invoice in a foreign currency
Pick the currency and the day the customer paid. We show the NBP average rate of the last business day before that day, the table number and VAT converted to złoty: exactly what the invoice needs.
Example: payment on a Monday
- Order
- VAT EUR 100.00, paid on Monday 19.10.2026
- Last business day before payment
- Friday 16.10.2026
- NBP average rate
- 1 EUR = 4.3661 PLN, table A no. 202/A/NBP/2026
- VAT in złoty
- PLN 436.61
Rate from NBP table A published on 16.10.2026. Saturday and Sunday are not business days, so a Monday payment takes Friday's rate.
Where the rate comes from
- Art. 31a(1) of the Polish VAT Act: amounts in a foreign currency are converted at the NBP average rate of the last business day before the tax point.
- In an online store paid up front, the tax point is usually the payment date (art. 19a(8)), so the business day before payment counts. A Monday payment takes Friday's rate; a payment on 2 January takes the rate of 31 December.
- VAT converted to złoty is shown separately on the invoice (fields P_14_xW in KSeF). A correction uses the rate of the original invoice.
- We fetch the rate live from the official API of Narodowy Bank Polski (api.nbp.pl), table A, published on business days.
The calculator helps but does not replace a tax adviser. In unusual cases (advance payments, continuous supplies) the tax point may differ.